/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * Neither the name of the HISP project nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.program;

import static com.google.common.base.Preconditions.checkNotNull;
import static org.hisp.dhis.parser.expression.ParserUtils.assumeProgramExpressionProgramAttribute;
import static org.hisp.dhis.parser.expression.ParserUtils.assumeStageElementSyntax;
import static org.hisp.dhis.parser.expression.antlr.ExpressionParser.A_BRACE;
import static org.hisp.dhis.parser.expression.antlr.ExpressionParser.ExprContext;
import static org.hisp.dhis.parser.expression.antlr.ExpressionParser.HASH_BRACE;

import java.util.Set;
import org.hisp.dhis.parser.expression.antlr.ExpressionBaseListener;

/**
 * Traverse the ANTLR4 parse tree for a program expression to collect the UIDs for data elements and
 * program attributes.
 *
 * <p>Uses the ANTLR4 listener pattern.
 *
 * @author Jim Grace
 */
public class ProgramElementsAndAttributesCollecter extends ExpressionBaseListener {
  private Set<String> items;

  private AnalyticsType analyticsType;

  // -------------------------------------------------------------------------
  // Constructor
  // -------------------------------------------------------------------------

  public ProgramElementsAndAttributesCollecter(Set<String> items, AnalyticsType analyticsType) {
    checkNotNull(items);
    checkNotNull(analyticsType);

    this.items = items;
    this.analyticsType = analyticsType;
  }

  // -------------------------------------------------------------------------
  // ANTLR Listener methods
  // -------------------------------------------------------------------------

  @Override
  public void enterExpr(ExprContext ctx) {
    if (ctx.it == null) {
      return;
    }

    switch (ctx.it.getType()) {
      case HASH_BRACE:
        assumeStageElementSyntax(ctx);

        String programStageId = ctx.uid0.getText();
        String dataElementId = ctx.uid1.getText();

        if (AnalyticsType.ENROLLMENT.equals(analyticsType)) {
          items.add(programStageId + "_" + dataElementId);
        } else {
          items.add(dataElementId);
        }
        break;

      case A_BRACE:
        assumeProgramExpressionProgramAttribute(ctx);

        String attributeId = ctx.uid0.getText();

        items.add(attributeId);

        break;

      default:
        break;
    }
  }
}
